How can you enforce data integrity in Azure SQL Database?

Enforcing data integrity in an Azure SQL Database is best achieved through the use of constraints, such as primary keys, foreign keys, and check constraints.

Primary keys ensure that each record in a table is unique and not null, providing a reliable method for identifying each row. Foreign keys establish a relationship between tables by ensuring that a value in one table corresponds to a valid entry in another, thereby maintaining referential integrity. Check constraints allow you to impose certain rules on the data in a column for validation purposes—ensuring that the values entered conform to specific criteria.

This approach ensures that the data adheres to defined standards and relationships, minimizing the risk of data anomalies and maintaining the overall quality of the dataset. Employing constraints directly addresses the core principles of data integrity: accuracy, consistency, and reliability.

In contrast, adding indexes primarily enhances the performance of data retrieval and does not directly influence the integrity of the data itself. Increasing the size of the database pertains more to capacity planning and storage management rather than data integrity. Automatic backups are crucial for data recovery and protection but do not enforce any rules that govern the integrity of the data stored within the database. Thus, the best method for enforcing data integrity is through the application of constraints.